pt-show-grants -u root --ask-pass
{{Enter password: }}
-- Grants dumped by pt-show-grants
-- Dumped from server Localhost via UNIX socket, MySQL 10.2.16-MariaDB at 2018-08-15 19:02:27
DBD::mysql::db selectall_arrayref failed: Unknown column 'account_locked' in 'where clause' [for Statement "SELECT DISTINCT User, Host FROM mysql.user  WHERE NOT ( `account_locked`="Y" AND  `password_expired`="Y" AND  `authentication_string`="" )  ORDER BY User, Host"] at /usr/bin/pt-show-grants line 1921, <STDIN> line 1.

https://jira.percona.com/browse/PT-1568 says fixed but still there for MariaDB 10.2 with 3.0.11